U.S. Rep. Stephen Lynch on Friday expressed outrage at President Donald Trump's opposition to further funding the United States Postal Service, a move the congressman said is in order to benefit Trump's reelection campaign.

Lynch also criticized Postmaster General Louis DeJoy for his handling of the USPS, which has recently been experiencing mail delays and staff shortages.

“What [Trump is] doing right now, we believe, is beyond his jurisdiction, ” Lynch said during an interview with Boston Public Radio. “Congress ... is responsible for making sure the postal service delivers the mail. So, right now he has the postmaster general, a handpicked person who’s really a fundraiser for the president and someone who has heavily invested in competitors to the post office, and he’s taking drastic measures to limit the resources that the post office has to deliver the mail.”

Trump has previously said that heopposes further funding to the Postal Service, particularly because he believes it will be used to support mail-in voting programs. At a press conference last week, Trump said he would not veto funding for the USPS if it was included in legislation sent to him, but doubled down on his opposition to mail-in voting.

“The reason the post office needs that much money is they have all of these millions of ballots coming in from nowhere and nobody knows from where and where they’re going,” Trump said during the press conference.

Lynch said Friday that the House Committee on Oversight and Reform is launching an investigation into DeJoy’s actions. He also advocated for taking the issue to federal court to enforce Congress’ jurisdiction over the governing of the postal service, and called Trump’s actions unconstitutional.

“I think it is becoming increasingly apparent that we are going to have to take legal action. Go into federal court, and assert the jurisdiction of the Congress over the delivery of the mail. That’s the only timely response I think we have,” Lynch said. “Otherwise, because we believe the administration will just engage in foot dragging and obstruction. But I think it’s the only thing we can do at this point to really amplify the concern that's going on here about whether or not this election will be allowed to proceed in any normal fashion.”

Lynch said that DeJoy’s reforms have made it significantly more difficult for postal workers to efficiently do their jobs. At a general mail sorting facility in South Boston, Lynch said, DeJoy has removed six high-speed mail sorting machines, which has significantly slowed down mail service.

According to reporting from The Washington Post on Friday, the USPS warned 46 states, including Massachusetts, that it could not guarantee all mailed-in ballots will be delivered in time to be counted for the November election.